Siphon spillway



G. F. STICKNEY. SIPHON SPILLWAY. APPLICATION FILED FEB.I8;1921.

Patented Jan. 31,1922.

um stern PATENT OFFICE.

GEORGE F. STICKNEY, OF ALBANY, NEW YORK.

sirnon SPILLWAY.

Specification of Letters Patent. Patgnted J 31 1922 Application filed February 18, 1921. Serial No. 446,052.

To all whom it may concern:

Be it known that I, GEORGE F. Srronnnr, a citizen of the United States, residing at Albany, in the countyof Albany and State I I U siphon s large the throat is high anda conof New York, have invented certain new and useful Improvements in Siphon 'Spillvvays;.

and I do declare the following to be a full,

clear, and exact description of the invention, such as will enable others skilled 1n the art to which it appertains to make and use the. same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My invention relates to siphons used in dams, spillways or waste weirs, for the purpose of discharging water and particularly to methods of priming siphons which have 'structed, the siphon consists of an invertedtheir throats wholly or in part below the high, or flood water, stage controlled by said siphons.

In siphon spillways heretofore con- U'shaped conduit through adam, with its throat entirely above the low water level;

an upstream leg that extends from the throat to the up-streamface of the dam, terminating in an inlet below the water level; a clown-stream leg extending from thethroat to an outlet in the clown-stream the dam at about the lowwvater level.

In such 'siphons priming is effected by a raise in the water level above the dam,

suflicient to seal the siphon against the entrance of air and to provide a flow that will displace' and carry out the air confined therein, after which the full siphonic flow j to sodesign the dam or spillway as to make is established. 7

When the water level above the dam is drawn down, sufliciently to uncover the air vent, air is admitted to the throat of the] the difference between the high and low stages of the pool above the dam as small as possible and,for reasons of economy, it it desirable to make the capacity of the spillway as large as possible, thus reducing to a minimum the length of the structure necessary to pass a given volume of Water. d When .the cross-sectional area of the 991,907, [granted to ;George F3 Stickney May 9, 19 11 and Patent 1,083,995, granted to William Russell Davis and George F. Stickney, January 13,, 1914:.

This specification, with accompanying drawings, describes a distinctly new method of constructing asiphon'spillway, as heretofore explained,- by which the siphon will be primed and put in operation with a less raise in the Water level above thefspillway and it is applicable to siphons of larger size than those 7, heretofore considered.

The new, form of construction consists in introducing a break in the plane ofthe back;wall of the clown-stream ,leg of the siphon, suchthat the stream of waterflowing through the leg will be deflected so that a jet; of water. is formed .which jumps across the leg and 'zimpinges against the far wall and, in doing this, makes a diaphragm of water inthe down-stream leg.

Priming is effected when there is a slight raise in the water level above the spillway, sufficient to seal the throat of; the siphon 'againstthe entrance of air through the upstream leg or the air vent, and to produce a flow ofiwaterfthr'oughthe siphon.

- Tater spills through the throat of the siphon and flOWS' ClOWI1 the down-stream leg to the break in the plane of the back-Wall I whereit is deflected, a jet is formed which vjumps across the vleg'and impinges against the far wall'makin'g a diaphragm of Water inthe down-stream leg that seals theupper portion of the siphon against the entrance per portion of, the siphon.

of air from below the jet, thus isolating a volume of air that is entrapped in the upper part of the siphon.

The jet of water, in impinging agalnst the far wall of the down-stream leg, breaks into foam and becomes impregnated with air that is in contact with its upper surface. This air is carried away by the flowlng stream and is thus abstracted from the up closed in the upper part of the siphon is entirely removed, the siphon is primed and the full flow is established.

Referring to the drawings, in which like parts are similarly designated, Figure 1 is a section of a dam, taken through a siphon which. has an inclined down-stream leg and which has a high throat, the lower edge of which is to be placed, approximately, at the low water stage above the dam, with a break in the plane of the back-wall of the down stream leg, made by curving the back-wall outward so as to form an'ofY-set, the break being located at suflicient distance below the throat. level to insure that the water will acquire the velocity necessary to jump across the leg.

Figure 2 is a section of a dam, taken through a siphon which has an inclined down-stream leg and which has a high throat, the lower edge of which is to be placed, approximately, at the low water stage above the dam, with a break in the plane of the back-wall of the down-stream leg made by curvlng the surface outward with a reverslng curveso as to form an offset, the break being located at sufficient distance below the throat level to insure that j the water will acquire the velocity necessary to jump across the leg.

"1F igure '3 is 'a section of a dam, taken through a siphon which has .a vertical down-stream leg and which has a high throat, the lower edge .of which is to be 'placed, approximately, at the low water Stage above the dam, with abreak in the P12111'C of the back-wall of the down-stream 'leg formedib y curving the back-wall outward so as tomake an off-set, the break being located at sufficient distance below the throat level to insure that the water will acqulre the velocity necessary to jump across -the'le g. i 7

Figure 4 is a section of a dam, taken through a siphon which has a vertical downstream leg and which has a high throat, the lower edge of which is to be placed, approximately, at the low water level above the dam, with a break in the plane of the backwall of the clown-stream leg made by curving the surface outward with a reversing curve so as to form an off-set in the leg, the break being located at suilicient distance below the throat level to insure that-the water will acquire the velocity necessary to jump across the leg.

Figure 5 shows the construction at the outlet of a siphon when such outlet dis charges high up on a dam, or where it is not necessary that the outfiowing water shall issue in a horizontal direction.

These figures indicate the siphons to be constructed of masonry, preferably of concrete, though any suitable material may be used in their construction.

Referring to Figs. 1 and 3; 1 is the upstream face of the dam; 2 is the downstream face; 3 is the top and '4 is the bottom, which is to rest on the customary foundations; 5 is an air vent, at about the low water plane; 6 is the inlet, placed below the low water stage; is the up -stream leg; 8 is the throat; 9 is the down-stream leg; 10-is the outlet, flared upward somewhat so that air bubbles in the water will travel outward, in case the outlet is submerged; 11 is the break in the plane of the backwall of the down stream leg, made by a simple curve and forming an oif-set; 13 is the jet of water and the diaphragm in the down-stream leg which seals the leg against the entrance of air from below and removes the air enclosed in the siphon above'the jet; 14 is the high water surface above the dam; 15 is the water surface below the dam, located some distance below where thejet strikes the outer wall of the clown-stream leg.

Referring to Figs. 2 and 1; 1 is the upstream face of the dam; 2 is the down-stream face; 3 is the top and 4 is the bottom, which is to rest on the customary foundations; :3 is an air vent at about the low water stage; 6 is the inlet placed below the low water stage; 7 is the upstream leg; 8 is the throat; 9 is the down-stream leg; 10 is the outlet, flared upward somewhat so that air bubbles in the water Willtravel outward, in case the. outlet is submerged; 12 is the break in the plane of the back-wall of the down-stream leg, made by a-revers:

dam, located some distance below where the jet strikes the outer wall ofthe down stream leg.

Referring to Fig. 5, 2 is the down-stream faceof the dam; 9 is the down-stream leg; 10 is the outlet; 12 is a break in the plane 'ofthe back-wall of the down-streamleg;

the latter point, where it is deflected by the curve and forms the jet, 13, which jumps across the clown-stream leg, 9, and forms a diaphragm in the leg that seals it against the entrance of air from below the jet.

This jet, 13, impinges against the outer wall of the down-stream leg, 9, breaks into foam and becomes impregnated with air in contact with its upper surface which air is carried away by the flowing stream and is thus abstracted from the upper part of the siphon.

As the enclosed air is removed the portion remaining in the siphon is rarefied and its pressure is reduced to below that of the atmosphere.

The atmospheric pressure on the free water surface, 14:, forces the water up to a higher level in the throat, 8, the depth of the overflowing stream increases both in volume and in capacity for removing the enclosed air at the jet, 13.

This action progresses until the siphon 1s completely filled with water, primlng 1s effected and the full siphonic flow is established. a 1 a j The action of the siphons shown in Figs. 2 and 4 is as follows V When the water surface above the dam, 14, raises so as to submerge the air vent, 5, water flows up the lip-stream leg, 7, through the throat, 8, and down the insideof the down-stream leg, 9, to the break in the plane of the back-wall, 12, having acquired con siderable velocity when it reaches the latter point, where it is deflected by the curve and forms the jet, 13, which jumps across the down-stream leg, 9, and forms a diaphragm in the leg that seals it against the entrance of air from below the jet, 13. v

This jet, 13, impinges against the outer wall of the down-stream leg, 9, breaks into foam and becomes impregnated with air in contact with its upper surface which air is carried away by the flowing stream and is surface, 14:, forces the water up to a higher 7 flowing stream increases both in volume'and in capacity for removing the enclosed air at the jet, 13. i

level in the throat,'8, the depth of the over- This action progresses until the siphon is completely filled with water, priming is effected and the full siphonic flow is established.

What I claim as my invention and desire to secure by Letters Patent is 1. A siphon spillway for dams, waste weirs and the like, comprising an inverted substantially U shaped conduit with unequal legs the shorter leg opening through the upstream face of the structure at a point below the normal low water level, the longer leg opening through the down. stream face at the desired point of discharge; andmeans in said longer leg for causing a stream of water flowing down one side of said leg to be projected across and to seal said'leg with a diaphragm of water.

2. A siphon spillway for dams, waste weirs and the like, comprising an inverted substantially U shaped conduit with unequal legs, the shorter leg opening through the upstream face of the structure preferably at a point some distance below the normal low water level and the longer leg opening through the down stream face at the desired point of discharge; means in said longer leg for causing water flowing down one side thereof to be projected across and to seal sald leg with a diaphragm of water; and an air vent adapted to admit air to the throat of the siphon when the water on the up-;

stream side of the structure is below the normal low water level.

3. A siphon spillway for dams, waste weirs and the like, comprising an invertedsubstantially U shaped conduit with unequal loo legs the shorter leg opening through the up stream face of the structure at a point below the normal low water level, the longer leg openmg through the down stream face at the desired point of discharge and a 'curved' ledge formed in saidlonger leg and adapted" to deflect a stream of waterflowing down one side thereof and cause it to be projected across said leg so as to form a diaphragm of jvater and seal said leg against air from beow. V r

4. In a siphon spillway for dams, waste weirs and the like, aninverted and substantially U shaped conduit leading from a point below the normal low water level on the up stream side of the structure to the desired point of discharge on the downstream side thereof; an air Vent adanted to admit air to 5 the throat of the siphon conduit when the water on the upstream side is below the normal low water level; and means formed in the discharge leg of said conduit adapted to deflect water flowing down one side thereof 10 and cause it to be projected across and to seal said conduit by forming therein a Water diaphragm and substantially as shown and described.

in testimony whereof I have affixed my signature in the presence of two witnesses.

GEORGE STICKNEY Witnesses Wu. RUssELL DAVIS, M. H. LLEWELLYN. 

